JP2005259550A - Organic el device and display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a very stable organic EL device and a display. <P>SOLUTION: In this organic EL device 1, at least a negative electrode 3, a luminous layer 4, a metal oxide layer 5 and a positive electrode 6 are laminated on substrate 2 in this order. Preferably, the metal oxide layer 5 comprises at least one kind selected from a group of molybdenum oxide, vanadium oxide, oxidation rhenium, ruthenium oxide, tungsten oxide, zinc oxide, titanium oxide and copper oxide. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to consumer and industrial displays, specifically, organic EL (electroluminescence) elements and display devices suitable as displays for mobile phones, PDAs, car navigation systems, monitors, TVs and the like.

  The organic EL display device includes an organic EL element in which a light emitting layer is sandwiched between opposed electrodes. When a voltage is applied between both electrodes of the organic EL element, electrons injected from one electrode and holes injected from the other electrode are recombined in the light emitting layer. The organic light emitting molecules in the light emitting layer are once excited by the recombination energy, and then return from the excited state to the ground state. The organic EL element emits light by taking out the energy released at this time as light.

  An organic EL element is formed on a substrate, but is roughly classified into two types depending on the light extraction side. That is, a top emission type that extracts light from the opposite side of the substrate and a bottom emission type that extracts light from the substrate side. When a TFT (thin film transistor) is formed on a substrate, the top emission type is preferable because the TFT prevents light extraction in the bottom emission type. In this case, it is necessary to arrange a transparent electrode in the light extraction direction. In an organic EL element, ITO is generally used as a transparent electrode in many cases, but the work function of ITO is as high as 4.5 eV or more, which is greatly different from the work function preferable as a cathode (4 eV or less). Therefore, an organic EL element in which the substrate / TFT / cathode / light emitting layer / anode are laminated in this order and ITO is used as the anode is considered. However, in order to form ITO, it is necessary to perform sputtering at a substrate temperature of 200 ° C. or higher. For this reason, when the anode is made of an ITO film, the layer structure of the organic EL element changes, which may cause problems such as a decrease in light emission efficiency, generation of leakage current, and a decrease in element life.

  Therefore, it has been proposed to form a metal thin film as a protective film on the hole injection layer and to form a transparent anode on the protective film (for example, Patent Document 1).

On the other hand, it has been proposed to combine a transparent electrode with various layers. For example, Patent Document 2 discloses a metal thin film and a transparent electrode layer, Patent Document 3 discloses a metal thin film and an amorphous transparent electrode layer, and Patent Document 4 discloses a metal thin film, an amorphous transparent electrode layer, and a metal. Document 5 discloses a metal thin film and a semiconductor thin film.
Japanese Patent Laid-Open No. 06-290873 JP 08-185984 A Japanese Patent Laid-Open No. 10-162959 JP-A-10-294182 JP 2000-048966 A

As a method for protecting the light emitting layer and improving the stability of the organic EL device, another method has been demanded.
An object of the present invention is to provide an organic EL element and a display device having high stability.

As a result of intensive studies, the present inventors have found that stability can be enhanced by forming a metal oxide layer to protect the light emitting layer, and the present invention has been completed.
According to the present invention, the following organic EL elements and display devices can be provided.

  According to the present invention, a highly stable organic EL element and display device can be provided.

  As shown in FIG. 1A, the present invention is an organic EL element 1 in which at least a cathode 3, a light emitting layer 4, a metal oxide layer 5, and an anode 6 are laminated in this order on a substrate 2. In the organic EL element 1, since the anode 6 can be formed on the metal oxide layer 5 on the light emitting layer 4, the light emitting layer 4 is prevented from being damaged when the anode 6 is formed by sputtering or the like. be able to.

  The organic EL element 1 of the present invention can be provided with an intervening layer as necessary. For example, as shown in FIG. 1B, a metal layer 7 can be provided between the metal oxide layer 5 and the anode 6 in order to improve the light emission efficiency.

  Moreover, as shown in FIG.1 (c), the anode 6 can also be comprised from the electrically conductive film 6a and the protective film 6b. By comprising in this way, the damage of the organic EL element by oxygen and a water | moisture content can be prevented.

  1A, 1B, and 1C, the organic EL element 1 may be a top emission type that extracts light from the side opposite to the substrate 2 or a bottom emission type that extracts light from the substrate 2 side. . In the top emission type, the anode is a transparent electrode and the cathode is a reflective electrode. In the bottom emission type, the anode is a reflective electrode and the cathode is a transparent electrode.

Although the typical structural example of organic EL elements other than FIG. 1 is shown below, this invention is not limited to this.
(I) Cathode / light emitting layer / hole injection layer / metal oxide layer / anode (ii) Cathode / light emitting layer / hole transport layer / hole injection layer / metal oxide layer / anode (iii) Cathode / electron injection Layer / light emitting layer / hole injection layer / metal oxide layer / anode (iv) cathode / electron injection layer / light emitting layer / hole transport layer / hole injection layer / metal oxide layer / anode (v) cathode / electron Injection layer / electron transport layer / light emitting layer / hole injection layer / metal oxide layer / anode (vi) cathode / electron injection layer / electron transport layer / light emitting layer / hole transport layer / hole injection layer / metal oxide Layer / anode (vii) cathode / electron injection layer / electron transport layer / light emitting layer / hole transport layer / hole injection layer / metal oxide layer / metal layer / anode (viii) cathode / electron injection layer / electron transport layer / Light emitting layer / hole transporting layer / hole injection layer / metal layer / metal oxide layer / anode (ix) cathode / electron injection layer / electron transport layer / light emitting layer / hole transport layer / hole injection layer / metal Oxide layer / conductivity Layer / Metal layer / Protective layer Among these, the configurations (v) and (vi) are preferable.

Below, each member is demonstrated.
(1) Substrate The organic EL device of the present invention is produced on a substrate.
As the substrate, a glass plate, a polymer plate or the like is preferably used. As the glass plate, soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, quartz and the like are particularly preferable. As the polymer plate, polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, polysulfone and the like are preferable.

(2) Anode The anode preferably has a work function of 4.5 eV or more. Examples of the anode include indium tin oxide alloy (ITO), indium zinc oxide alloy (IZO), tin oxide (NESA), gold, silver, platinum, copper, and the like. Among these, an indium zinc oxide alloy (IZO) is particularly preferable because it can be formed at room temperature, and since it is highly amorphous, it is difficult for the anode to peel off.

  When the anode is formed by stacking a conductive film and a protective film, the conductive film can be appropriately selected from materials used for the anode. The protective film is preferably formed from an oxide, nitride or oxynitride of at least one element selected from the group consisting of Si, Ge, Mg, Ta, Ti, Zn, Sn, In, Pb and Bi. Is done. Also, preferably selected from the group consisting of Mo, V, Cr, W, Ni, Co, Mn, Ir, Pt, Pd, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er and Yb. And at least one element oxide, nitride or oxynitride.

  In the case where light emitted from the light emitting layer is extracted from the anode side, the protective film is preferably light transmissive. Specifically, the transmittance for light emission is preferably greater than 10%. More preferably, it is 30% or more, and further preferably 50% or more.

The sheet resistance of the anode is preferably 1000Ω / □ or less. More preferably, it is 800 ohm / square, More preferably, it is 500 ohm / square.
When light emission is taken out from the anode, it is preferable that the transmittance of the anode for light emission is greater than 10%. More preferably, it is 30% or more, More preferably, it is 50% or more.

The film thickness of the anode varies depending on the material, but is usually selected in the range of 10 nm to 1 μm, preferably 10 to 200 nm. When the anode is formed by laminating a conductive film and a protective film, the anode is usually selected in the range of 10 nm to 1 μm of the conductive film and 10 nm to 100 nm of the protective film.
The anode film formation is not particularly limited as long as it is a known film formation method. Preferably, the vapor deposition method, the sputtering method, and the coating method are good.

(3) Light-Emitting Layer As a method for forming the light-emitting layer, a known method such as a vapor deposition method, a spin coating method, or an LB method can be applied. Further, as disclosed in JP-A-57-51781, a binder such as a resin and a material compound are dissolved in a solvent to form a solution, and then this is thinned by a spin coating method or the like. In addition, a light emitting layer can be formed.

（式中、Ａｒ^１は核炭素数６〜５０の芳香族環、Ｘは置換基、ｍは１〜５の整数、ｎは０〜６の整数である。） As a material used for the light-emitting layer, a known material that has a long lifetime can be used, but a material represented by the formula (1) is preferably used as the light-emitting material.

(In the formula, Ar ¹ is an aromatic ring having 6 to 50 nuclear carbon atoms, X is a substituent, m is an integer of 1 to 5, and n is an integer of 0 to 6.)

Specifically, Ar ¹ is a phenyl ring, naphthyl ring, anthracene ring, biphenylene ring, azulene ring, acenaphthylene ring, fluorene ring, phenanthrene ring, fluoranthene ring, acephenanthrylene ring, triphenylene ring, pyrene ring, chrysene ring Naphthacene ring, picene ring, perylene ring, pentaphen ring, pentacene ring, tetraphenylene ring, hexaphen ring, hexacene ring, rubicene ring, coronene ring, trinaphthylene ring, and the like.

  Preferred examples include phenyl ring, naphthyl ring, anthracene ring, acenaphthylene ring, fluorene ring, phenanthrene ring, fluoranthene ring, triphenylene ring, pyrene ring, chrysene ring, perylene ring, trinaphthylene ring and the like.

  More preferable examples include a phenyl ring, a naphthyl ring, an anthracene ring, a fluorene ring, a phenanthrene ring, a fluoranthene ring, a pyrene ring, a chrysene ring, and a perylene ring.

  Specifically, X is a substituted or unsubstituted aromatic group having 6 to 50 nuclear carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 5 to 50 nuclear atoms, a substituted or unsubstituted carbon number of 1 An alkyl group having ˜50, a substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, a substituted or unsubstituted aralkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryloxy group having 5 to 50 nucleus atoms, Substituted or unsubstituted arylthio group having 5 to 50 nucleus atoms, substituted or unsubstituted carboxyl group having 1 to 50 carbon atoms, substituted or unsubstituted styryl group, halogen group, cyano group, nitro group, hydroxyl group, etc. is there.

  Examples of the substituted or unsubstituted aromatic group having 6 to 50 nuclear carbon atoms include phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 1- Phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, 1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group, 1-pyrenyl group, 2-pyrenyl group, 4- Pyrenyl group, 2-biphenylyl group, 3-biphenylyl group, 4-biphenylyl group, p-terphenyl-4-yl group, p-terphenyl-3-yl group, p-terphenyl-2-yl group M-terphenyl-4-yl group, m-terphenyl-3-yl group, m-terphenyl-2-yl group, o-tolyl group, m-tolyl group, p-tolyl group, p t-butylphenyl group, p- (2-phenylpropyl) phenyl group, 3-methyl-2-naphthyl group, 4-methyl-1-naphthyl group, 4-methyl-1-anthryl group, 4′-methylbiphenylyl Group, 4 "-t-butyl-p-terphenyl-4-yl group, 2-fluorenyl group, 9,9-dimethyl-2-fluorenyl group, 3-fluoranthenyl group and the like.

  Preferably a phenyl group, 1-naphthyl group, 2-naphthyl group, 9-phenanthryl group, 1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group, 2-biphenylyl group, 3-biphenylyl group, 4-biphenylyl group, o-tolyl group, m-tolyl group, p-tolyl group, pt-butylphenyl group, 2-fluorenyl group, 9,9- A dimethyl-2-fluorenyl group, a 3-fluoranthenyl group, etc. are mentioned.

  Examples of the substituted or unsubstituted aromatic heterocyclic group having 5 to 50 nucleus atoms include 1-pyrrolyl group, 2-pyrrolyl group, 3-pyrrolyl group, pyrazinyl group, 2-pyridinyl group, 3-pyridinyl group, 4-pyridinyl group, 1-indolyl group, 2-indolyl group, 3-indolyl group, 4-indolyl group, 5-indolyl group, 6-indolyl group, 7-indolyl group, 1-isoindolyl group, 2-isoindolyl group, 3-isoindolyl group, 4-isoindolyl group, 5-isoindolyl group, 6-isoindolyl group, 7-isoindolyl group, 2-furyl group, 3-furyl group, 2-benzofuranyl group, 3-benzofuranyl group, 4-benzofuranyl group, 5-benzofuranyl group, 6-benzofuranyl group, 7-benzofuranyl group, 1-isobenzofuranyl group, 3-isobenzofuran group Group, 4-isobenzofuranyl group, 5-isobenzofuranyl group, 6-isobenzofuranyl group, 7-isobenzofuranyl group, quinolyl group, 3-quinolyl group, 4-quinolyl group, 5- Quinolyl group, 6-quinolyl group, 7-quinolyl group, 8-quinolyl group, 1-isoquinolyl group, 3-isoquinolyl group, 4-isoquinolyl group, 5-isoquinolyl group, 6-isoquinolyl group, 7-isoquinolyl group, 8- Isoquinolyl group, 2-quinoxalinyl group, 5-quinoxalinyl group, 6-quinoxalinyl group, 1-carbazolyl group, 2-carbazolyl group, 3-carbazolyl group, 4-carbazolyl group, 9-carbazolyl group, 1-phenanthridinyl group 2-phenanthridinyl group, 3-phenanthridinyl group, 4-phenanthridinyl group, 6-phenanthridinyl group, 7-phena Thridinyl group, 8-phenanthridinyl group, 9-phenanthridinyl group, 10-phenanthridinyl group, 1-acridinyl group, 2-acridinyl group, 3-acridinyl group, 4-acridinyl group, 9-acridinyl group Group, 1,7-phenanthrolin-2-yl group, 1,7-phenanthrolin-3-yl group, 1,7-phenanthrolin-4-yl group, 1,7-phenanthrolin-5 -Yl group, 1,7-phenanthrolin-6-yl group, 1,7-phenanthrolin-8-yl group, 1,7-phenanthrolin-9-yl group, 1,7-phenanthroline -10-yl group, 1,8-phenanthrolin-2-yl group, 1,8-phenanthrolin-3-yl group, 1,8-phenanthrolin-4-yl group, 1,8-phen group Nansulolin-5-yl group, 1,8-phena Nsulolin-6-yl group, 1,8-phenanthrolin-7-yl group, 1,8-phenanthrolin-9-yl group, 1,8-phenanthrolin-10-yl group, 1,9- Phenanthrolin-2-yl group, 1,9-phenanthrolin-3-yl group, 1,9-phenanthrolin-4-yl group, 1,9-phenanthrolin-5-yl group, 1, 9-phenanthroline-6-yl group, 1,9-phenanthrolin-7-yl group, 1,9-phenanthrolin-8-yl group, 1,9-phenanthrolin-10-yl group, 1,10-phenanthrolin-2-yl group, 1,10-phenanthrolin-3-yl group, 1,10-phenanthrolin-4-yl group, 1,10-phenanthrolin-5-yl Group, 2,9-phenanthrolin-1-yl group, 2,9-phenanthroli -3-yl group, 2,9-phenanthrolin-4-yl group, 2,9-phenanthrolin-5-yl group, 2,9-phenanthrolin-6-yl group, 2,9-phen group Nansulolin-7-yl group, 2,9-phenanthrolin-8-yl group, 2,9-phenanthrolin-10-yl group, 2,8-phenanthrolin-1-yl group, 2,8 -Phenanthrolin-3-yl group, 2,8-phenanthrolin-4-yl group, 2,8-phenanthrolin-5-yl group, 2,8-phenanthrolin-6-yl group, 2 , 8-phenanthroline-7-yl group, 2,8-phenanthrolin-9-yl group, 2,8-phenanthrolin-10-yl group, 2,7-phenanthrolin-1-yl group 2,7-phenanthrolin-3-yl group, 2,7-phenanthrolin-4-yl group, , 7-phenanthroline-5-yl group, 2,7-phenanthrolin-6-yl group, 2,7-phenanthrolin-8-yl group, 2,7-phenanthrolin-9-yl group 2,7-phenanthrolin-10-yl group, 1-phenazinyl group, 2-phenazinyl group, 1-phenothiazinyl group, 2-phenothiazinyl group, 3-phenothiazinyl group, 4-phenothiazinyl group, 10- Phenothiazinyl group, 1-phenoxazinyl group, 2-phenoxazinyl group, 3-phenoxazinyl group, 4-phenoxazinyl group, 10-phenoxazinyl group, 2-oxazolyl group, 4-oxazolyl group, 5-oxazolyl group, 2-oxadiazolyl group, 5 -Oxadiazolyl group, 3-furazanyl group, 2-thienyl group, 3-thienyl group, 2-methylpyrrol-1-yl group, 2 -Methylpyrrol-3-yl group, 2-methylpyrrol-4-yl group, 2-methylpyrrol-5-yl group, 3-methylpyrrol-1-yl group, 3-methylpyrrol-2-yl group, 3 -Methylpyrrol-4-yl group, 3-methylpyrrol-5-yl group, 2-t-butylpyrrol-4-yl group, 3- (2-phenylpropyl) pyrrol-1-yl group, 2-methyl- 1-indolyl group, 4-methyl-1-indolyl group, 2-methyl-3-indolyl group, 4-methyl-3-indolyl group, 2-t-butyl 1-indolyl group, 4-t-butyl 1-indolyl group Group, 2-t-butyl 3-indolyl group, 4-t-butyl 3-indolyl group and the like.

  Examples of the substituted or unsubstituted alkyl group having 1 to 50 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, s-butyl group, isobutyl group, t-butyl group, n- Pentyl group, n-hexyl group, n-heptyl group, n-octyl group, hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 2-hydroxyisobutyl group, 1,2-dihydroxyethyl group, 1, 3-dihydroxyisopropyl group, 2,3-dihydroxy-t-butyl group, 1,2,3-trihydroxypropyl group, chloromethyl group, 1-chloroethyl group, 2-chloroethyl group, 2-chloroisobutyl group, 1, 2-dichloroethyl group, 1,3-dichloroisopropyl group, 2,3-dichloro-t-butyl group, 1,2,3-trichloropropyl group Bromomethyl group, 1-bromoethyl group, 2-bromoethyl group, 2-bromoisobutyl group, 1,2-dibromoethyl group, 1,3-dibromoisopropyl group, 2,3-dibromo-t-butyl group, 1,2, 3-tribromopropyl group, iodomethyl group, 1-iodoethyl group, 2-iodoethyl group, 2-iodoisobutyl group, 1,2-diiodoethyl group, 1,3-diiodoisopropyl group, 2,3-diiodo-t- Butyl group, 1,2,3-triiodopropyl group, aminomethyl group, 1-aminoethyl group, 2-aminoethyl group, 2-aminoisobutyl group, 1,2-diaminoethyl group, 1,3-diaminoisopropyl Group, 2,3-diamino-t-butyl group, 1,2,3-triaminopropyl group, cyanomethyl group, 1-cyanoethyl group, 2-cyanoethyl 2-cyanoisobutyl group, 1,2-dicyanoethyl group, 1,3-dicyanoisopropyl group, 2,3-dicyano-t-butyl group, 1,2,3-tricyanopropyl group, nitromethyl group, 1- Nitroethyl group, 2-nitroethyl group, 2-nitroisobutyl group, 1,2-dinitroethyl group, 1,3-dinitroisopropyl group, 2,3-dinitro-t-butyl group, 1,2,3-trinitropropyl Group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, 4-methylcyclohexyl group, 1-adamantyl group, 2-adamantyl group, 1-norbornyl group, 2-norbornyl group and the like.

  A substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms is a group represented by -OY, and examples of Y include methyl, ethyl, propyl, isopropyl, n-butyl, and s-butyl. Group, isobutyl group, t-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 2-hydroxyisobutyl Group, 1,2-dihydroxyethyl group, 1,3-dihydroxyisopropyl group, 2,3-dihydroxy-t-butyl group, 1,2,3-trihydroxypropyl group, chloromethyl group, 1-chloroethyl group, 2 -Chloroethyl group, 2-chloroisobutyl group, 1,2-dichloroethyl group, 1,3-dichloroisopropyl group, 2,3-dichloro-t-butyl group, , 2,3-trichloropropyl group, bromomethyl group, 1-bromoethyl group, 2-bromoethyl group, 2-bromoisobutyl group, 1,2-dibromoethyl group, 1,3-dibromoisopropyl group, 2,3-dibromo- t-butyl group, 1,2,3-tribromopropyl group, iodomethyl group, 1-iodoethyl group, 2-iodoethyl group, 2-iodoisobutyl group, 1,2-diiodoethyl group, 1,3-diiodoisopropyl group 2,3-diiodo-t-butyl group, 1,2,3-triiodopropyl group, aminomethyl group, 1-aminoethyl group, 2-aminoethyl group, 2-aminoisobutyl group, 1,2-diamino Ethyl group, 1,3-diaminoisopropyl group, 2,3-diamino-t-butyl group, 1,2,3-triaminopropyl group, cyanomethyl group, 1- Anoethyl group, 2-cyanoethyl group, 2-cyanoisobutyl group, 1,2-dicyanoethyl group, 1,3-dicyanoisopropyl group, 2,3-dicyano-t-butyl group, 1,2,3-tricyanopropyl Group, nitromethyl group, 1-nitroethyl group, 2-nitroethyl group, 2-nitroisobutyl group, 1,2-dinitroethyl group, 1,3-dinitroisopropyl group, 2,3-dinitro-t-butyl group, 1, Examples include 2,3-trinitropropyl group.

  Examples of the substituted or unsubstituted aralkyl group having 1 to 50 carbon atoms include benzyl group, 1-phenylethyl group, 2-phenylethyl group, 1-phenylisopropyl group, 2-phenylisopropyl group, and phenyl-t-butyl. Group, α-naphthylmethyl group, 1-α-naphthylethyl group, 2-α-naphthylethyl group, 1-α-naphthylisopropyl group, 2-α-naphthylisopropyl group, β-naphthylmethyl group, 1-β- Naphthylethyl group, 2-β-naphthylethyl group, 1-β-naphthylisopropyl group, 2-β-naphthylisopropyl group, 1-pyrrolylmethyl group, 2- (1-pyrrolyl) ethyl group, p-methylbenzyl group, m -Methylbenzyl group, o-methylbenzyl group, p-chlorobenzyl group, m-chlorobenzyl group, o-chlorobenzyl group, p-bromoben Group, m-bromobenzyl group, o-bromobenzyl group, p-iodobenzyl group, m-iodobenzyl group, o-iodobenzyl group, p-hydroxybenzyl group, m-hydroxybenzyl group, o-hydroxybenzyl group P-aminobenzyl group, m-aminobenzyl group, o-aminobenzyl group, p-nitrobenzyl group, m-nitrobenzyl group, o-nitrobenzyl group, p-cyanobenzyl group, m-cyanobenzyl group, o -Cyanobenzyl group, 1-hydroxy-2-phenylisopropyl group, 1-chloro-2-phenylisopropyl group and the like.

  A substituted or unsubstituted aryloxy group having 5 to 50 nuclear atoms is represented as -OY ', and examples of Y' include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthryl group, and a 2-anthryl group. Group, 9-anthryl group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, 1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group, 1-pyrenyl Group, 2-pyrenyl group, 4-pyrenyl group, 2-biphenylyl group, 3-biphenylyl group, 4-biphenylyl group, p-terphenyl-4-yl group, p-terphenyl-3-yl group, p-terphenyl-2-yl group, m-terphenyl-4-yl group, m-terphenyl-3-yl group, m-terphenyl-2-yl group, o-tolyl group, -Tolyl group, p-tolyl group, pt-butylphenyl group, p- (2-phenylpropyl) phenyl group, 3-methyl-2-naphthyl group, 4-methyl-1-naphthyl group, 4-methyl- 1-anthryl group, 4′-methylbiphenylyl group, 4 ″ -t-butyl-p-terphenyl-4-yl group, 2-pyrrolyl group, 3-pyrrolyl group, pyrazinyl group, 2-pyridinyl group, 3- Pyridinyl group, 4-pyridinyl group, 2-indolyl group, 3-indolyl group, 4-indolyl group, 5-indolyl group, 6-indolyl group, 7-indolyl group, 1-isoindolyl group, 3-isoindolyl group, 4- Isoindolyl group, 5-isoindolyl group, 6-isoindolyl group, 7-isoindolyl group, 2-furyl group, 3-furyl group, 2-benzofuranyl group, 3-benzofuranyl group 4-benzofuranyl group, 5-benzofuranyl group, 6-benzofuranyl group, 7-benzofuranyl group, 1-isobenzofuranyl group, 3-isobenzofuranyl group, 4-isobenzofuranyl group, 5-isobenzofuranyl group Nyl group, 6-isobenzofuranyl group, 7-isobenzofuranyl group, 2-quinolyl group, 3-quinolyl group, 4-quinolyl group, 5-quinolyl group, 6-quinolyl group, 7-quinolyl group, 8 -Quinolyl group, 1-isoquinolyl group, 3-isoquinolyl group, 4-isoquinolyl group, 5-isoquinolyl group, 6-isoquinolyl group, 7-isoquinolyl group, 8-isoquinolyl group, 2-quinoxalinyl group, 5-quinoxalinyl group, 6 -Quinoxalinyl group, 1-carbazolyl group, 2-carbazolyl group, 3-carbazolyl group, 4-carbazolyl group, 1-phenanthridinyl Group, 2-phenanthridinyl group, 3-phenanthridinyl group, 4-phenanthridinyl group, 6-phenanthridinyl group, 7-phenanthridinyl group, 8-phenanthridinyl group, 9-phenanthridinyl group, 10-phenanthridinyl group, 1-acridinyl group, 2-acridinyl group, 3-acridinyl group, 4-acridinyl group, 9-acridinyl group, 1,7-phenanthroline-2 -Yl group, 1,7-phenanthrolin-3-yl group, 1,7-phenanthrolin-4-yl group, 1,7-phenanthrolin-5-yl group, 1,7-phenanthroline -6-yl group, 1,7-phenanthrolin-8-yl group, 1,7-phenanthrolin-9-yl group, 1,7-phenanthrolin-10-yl group, 1,8-phen group Nansulolin-2-yl group, 1,8- Phenanthrolin-3-yl group, 1,8-phenanthrolin-4-yl group, 1,8-phenanthrolin-5-yl group, 1,8-phenanthrolin-6-yl group, 1,8- Phenanthrolin-7-yl group, 1,8-phenanthroline-9-yl group, 1,8-phenanthrolin-10-yl group, 1,9-phenanthrolin-2-yl group, 1, 9-phenanthrolin-3-yl group, 1,9-phenanthrolin-4-yl group, 1,9-phenanthrolin-5-yl group, 1,9-phenanthrolin-6-yl group, 1,9-phenanthrolin-7-yl group, 1,9-phenanthrolin-8-yl group, 1,9-phenanthrolin-10-yl group, 1,10-phenanthrolin-2-yl Group, 1,10-phenanthrolin-3-yl group, 1,10-phenanth Rin-4-yl group, 1,10-phenanthrolin-5-yl group, 2,9-phenanthrolin-1-yl group, 2,9-phenanthrolin-3-yl group, 2,9- Phenanthrolin-4-yl group, 2,9-phenanthrolin-5-yl group, 2,9-phenanthrolin-6-yl group, 2,9-phenanthrolin-7-yl group, 2, 9-phenanthroline-8-yl group, 2,9-phenanthrolin-10-yl group, 2,8-phenanthrolin-1-yl group, 2,8-phenanthrolin-3-yl group, 2,8-phenanthrolin-4-yl group, 2,8-phenanthrolin-5-yl group, 2,8-phenanthrolin-6-yl group, 2,8-phenanthrolin-7-yl Group, 2,8-phenanthrolin-9-yl group, 2,8-phenanthrolin-10-yl Group, 2,7-phenanthrolin-1-yl group, 2,7-phenanthrolin-3-yl group, 2,7-phenanthrolin-4-yl group, 2,7-phenanthrolin-5 -Yl group, 2,7-phenanthroline-6-yl group, 2,7-phenanthrolin-8-yl group, 2,7-phenanthrolin-9-yl group, 2,7-phenanthroline -10-yl group, 1-phenazinyl group, 2-phenazinyl group, 1-phenothiazinyl group, 2-phenothiazinyl group, 3-phenothiazinyl group, 4-phenothiazinyl group, 1-phenoxazinyl group, 2-phenoxazinyl group, 3-phenoxazinyl group, 4-phenoxazinyl group, 2-oxazolyl group, 4-oxazolyl group, 5-oxazolyl group, 2-oxadiazolyl group, 5-oxadiazolyl group, 3-flazanyl group 2-thienyl group, 3-thienyl group, 2-methylpyrrol-1-yl group, 2-methylpyrrol-3-yl group, 2-methylpyrrol-4-yl group, 2-methylpyrrol-5-yl group, 3-methylpyrrol-1-yl group, 3-methylpyrrol-2-yl group, 3-methylpyrrol-4-yl group, 3-methylpyrrol-5-yl group, 2-t-butylpyrrol-4-yl Group, 3- (2-phenylpropyl) pyrrol-1-yl group, 2-methyl-1-indolyl group, 4-methyl-1-indolyl group, 2-methyl-3-indolyl group, 4-methyl-3- Indolyl group, 2-t-butyl 1-indolyl group, 4-t-butyl 1-indolyl group, 2-t-butyl 3-indolyl group, 4-t-butyl 3-indolyl group and the like can be mentioned.

  A substituted or unsubstituted arylthio group having 5 to 50 nuclear atoms is represented by —SY ″, and examples of Y ″ include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthryl group, and a 2-anthryl group. 9-anthryl group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, 1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group, 1-pyrenyl group 2-pyrenyl group, 4-pyrenyl group, 2-biphenylyl group, 3-biphenylyl group, 4-biphenylyl group, p-terphenyl-4-yl group, p-terphenyl-3-yl group, p -Terphenyl-2-yl group, m-terphenyl-4-yl group, m-terphenyl-3-yl group, m-terphenyl-2-yl group, o-tolyl group, m Tolyl group, p-tolyl group, pt-butylphenyl group, p- (2-phenylpropyl) phenyl group, 3-methyl-2-naphthyl group, 4-methyl-1-naphthyl group, 4-methyl-1 -Anthryl group, 4'-methylbiphenylyl group, 4 "-t-butyl-p-terphenyl-4-yl group, 2-pyrrolyl group, 3-pyrrolyl group, pyrazinyl group, 2-pyridinyl group, 3-pyridinyl Group, 4-pyridinyl group, 2-indolyl group, 3-indolyl group, 4-indolyl group, 5-indolyl group, 6-indolyl group, 7-indolyl group, 1-isoindolyl group, 3-isoindolyl group, 4-isoindolyl group Group, 5-isoindolyl group, 6-isoindolyl group, 7-isoindolyl group, 2-furyl group, 3-furyl group, 2-benzofuranyl group, 3-benzofuranyl group 4-benzofuranyl group, 5-benzofuranyl group, 6-benzofuranyl group, 7-benzofuranyl group, 1-isobenzofuranyl group, 3-isobenzofuranyl group, 4-isobenzofuranyl group, 5-isobenzofuranyl group Group, 6-isobenzofuranyl group, 7-isobenzofuranyl group, 2-quinolyl group, 3-quinolyl group, 4-quinolyl group, 5-quinolyl group, 6-quinolyl group, 7-quinolyl group, 8- Quinolyl group, 1-isoquinolyl group, 3-isoquinolyl group, 4-isoquinolyl group, 5-isoquinolyl group, 6-isoquinolyl group, 7-isoquinolyl group, 8-isoquinolyl group, 2-quinoxalinyl group, 5-quinoxalinyl group, 6- Quinoxalinyl group, 1-carbazolyl group, 2-carbazolyl group, 3-carbazolyl group, 4-carbazolyl group, 1-phenanthridinyl group 2-phenanthridinyl group, 3-phenanthridinyl group, 4-phenanthridinyl group, 6-phenanthridinyl group, 7-phenanthridinyl group, 8-phenanthridinyl group, 9 -Phenanthridinyl group, 10-phenanthridinyl group, 1-acridinyl group, 2-acridinyl group, 3-acridinyl group, 4-acridinyl group, 9-acridinyl group, 1,7-phenanthroline-2- Yl group, 1,7-phenanthrolin-3-yl group, 1,7-phenanthrolin-4-yl group, 1,7-phenanthrolin-5-yl group, 1,7-phenanthrolin- 6-yl group, 1,7-phenanthroline-8-yl group, 1,7-phenanthrolin-9-yl group, 1,7-phenanthrolin-10-yl group, 1,8-phenance Lorin-2-yl group, 1,8-Fu Nansulolin-3-yl group, 1,8-phenanthrolin-4-yl group, 1,8-phenanthrolin-5-yl group, 1,8-phenanthrolin-6-yl group, 1,8- Phenanthrolin-7-yl group, 1,8-phenanthroline-9-yl group, 1,8-phenanthrolin-10-yl group, 1,9-phenanthrolin-2-yl group, 1, 9-phenanthrolin-3-yl group, 1,9-phenanthrolin-4-yl group, 1,9-phenanthrolin-5-yl group, 1,9-phenanthrolin-6-yl group, 1,9-phenanthrolin-7-yl group, 1,9-phenanthrolin-8-yl group, 1,9-phenanthrolin-10-yl group, 1,10-phenanthrolin-2-yl Group, 1,10-phenanthrolin-3-yl group, 1,10-phenanthro N-4-yl group, 1,10-phenanthrolin-5-yl group, 2,9-phenanthrolin-1-yl group, 2,9-phenanthrolin-3-yl group, 2,9- Phenanthrolin-4-yl group, 2,9-phenanthrolin-5-yl group, 2,9-phenanthrolin-6-yl group, 2,9-phenanthrolin-7-yl group, 2, 9-phenanthroline-8-yl group, 2,9-phenanthrolin-10-yl group, 2,8-phenanthrolin-1-yl group, 2,8-phenanthrolin-3-yl group, 2,8-phenanthrolin-4-yl group, 2,8-phenanthrolin-5-yl group, 2,8-phenanthrolin-6-yl group, 2,8-phenanthrolin-7-yl Group, 2,8-phenanthrolin-9-yl group, 2,8-phenanthrolin-10-yl group 2,7-phenanthrolin-1-yl group, 2,7-phenanthrolin-3-yl group, 2,7-phenanthrolin-4-yl group, 2,7-phenanthrolin-5- Yl group, 2,7-phenanthrolin-6-yl group, 2,7-phenanthrolin-8-yl group, 2,7-phenanthrolin-9-yl group, 2,7-phenanthrolin- 10-yl group, 1-phenazinyl group, 2-phenazinyl group, 1-phenothiazinyl group, 2-phenothiazinyl group, 3-phenothiazinyl group, 4-phenothiazinyl group, 1-phenoxazinyl group, 2-phenoxazinyl group, 3 -Phenoxazinyl group, 4-phenoxazinyl group, 2-oxazolyl group, 4-oxazolyl group, 5-oxazolyl group, 2-oxadiazolyl group, 5-oxadiazolyl group, 3-flazanyl group, -Thienyl group, 3-thienyl group, 2-methylpyrrol-1-yl group, 2-methylpyrrol-3-yl group, 2-methylpyrrol-4-yl group, 2-methylpyrrol-5-yl group, 3 -Methylpyrrol-1-yl group, 3-methylpyrrol-2-yl group, 3-methylpyrrol-4-yl group, 3-methylpyrrol-5-yl group, 2-t-butylpyrrol-4-yl group 3- (2-phenylpropyl) pyrrol-1-yl group, 2-methyl-1-indolyl group, 4-methyl-1-indolyl group, 2-methyl-3-indolyl group, 4-methyl-3-indolyl group Group, 2-t-butyl 1-indolyl group, 4-t-butyl 1-indolyl group, 2-t-butyl 3-indolyl group, 4-t-butyl 3-indolyl group and the like.

  The substituted or unsubstituted carboxyl group having 1 to 50 carbon atoms is represented as —COOZ, and examples of Z include methyl, ethyl, propyl, isopropyl, n-butyl, s-butyl, and isobutyl. , T-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 2-hydroxyisobutyl group, 1, 2-dihydroxyethyl group, 1,3-dihydroxyisopropyl group, 2,3-dihydroxy-t-butyl group, 1,2,3-trihydroxypropyl group, chloromethyl group, 1-chloroethyl group, 2-chloroethyl group, 2-chloroisobutyl group, 1,2-dichloroethyl group, 1,3-dichloroisopropyl group, 2,3-dichloro-t-butyl group, 1, , 3-trichloropropyl group, bromomethyl group, 1-bromoethyl group, 2-bromoethyl group, 2-bromoisobutyl group, 1,2-dibromoethyl group, 1,3-dibromoisopropyl group, 2,3-dibromo-t- Butyl group, 1,2,3-tribromopropyl group, iodomethyl group, 1-iodoethyl group, 2-iodoethyl group, 2-iodoisobutyl group, 1,2-diiodoethyl group, 1,3-diiodoisopropyl group, 2 , 3-Diiodo-t-butyl group, 1,2,3-triiodopropyl group, aminomethyl group, 1-aminoethyl group, 2-aminoethyl group, 2-aminoisobutyl group, 1,2-diaminoethyl group 1,3-diaminoisopropyl group, 2,3-diamino-t-butyl group, 1,2,3-triaminopropyl group, cyanomethyl group, 1-sia Ethyl group, 2-cyanoethyl group, 2-cyanoisobutyl group, 1,2-dicyanoethyl group, 1,3-dicyanoisopropyl group, 2,3-dicyano-t-butyl group, 1,2,3-tricyanopropyl Group, nitromethyl group, 1-nitroethyl group, 2-nitroethyl group, 2-nitroisobutyl group, 1,2-dinitroethyl group, 1,3-dinitroisopropyl group, 2,3-dinitro-t-butyl group, 1, Examples include 2,3-trinitropropyl group.

  Examples of the substituted or unsubstituted styryl group include 2-phenyl-1-vinyl group, 2,2-diphenyl-1-vinyl group, 1,2,2-triphenyl-1-vinyl group, and the like.

Examples of the halogen group include fluorine, chlorine, bromine and iodine.
l is an integer of 1-5, preferably 1-2. m is an integer of 0-6, preferably 0-4.

When l ≧ 2, l Ar ^{1 s} may be the same or different.
When m ≧ 2, the m Xs may be the same or different.

Specific examples of the compound represented by the formula (1) are shown below.

（式中、Ａｒ^２〜Ａｒ^４は置換又は無置換の核炭素数６〜５０の芳香族基、置換又は無置換のスチリル基、ｐは１〜４の整数である。） Luminescent performance can be improved by adding a fluorescent compound as a dopant to the light emitting layer. As the dopant, a known material such as a long-life punt material can be used, but it is preferable to use a material represented by the formula (2) as a dopant material of the light emitting material.

(In the formula, Ar ^{2 to} Ar ⁴ are substituted or unsubstituted aromatic groups having 6 to 50 nuclear carbon atoms, substituted or unsubstituted styryl groups, and p is an integer of 1 to 4).

  Examples of the substituted or unsubstituted aromatic group having 6 to 50 nuclear carbon atoms include phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 1- Phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, 1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group, 1-pyrenyl group, 2-pyrenyl group, 4- Pyrenyl group, 2-biphenylyl group, 3-biphenylyl group, 4-biphenylyl group, p-terphenyl-4-yl group, p-terphenyl-3-yl group, p-terphenyl-2-yl group M-terphenyl-4-yl group, m-terphenyl-3-yl group, m-terphenyl-2-yl group, o-tolyl group, m-tolyl group, p-tolyl group, p t-butylphenyl group, p- (2-phenylpropyl) phenyl group, 3-methyl-2-naphthyl group, 4-methyl-1-naphthyl group, 4-methyl-1-anthryl group, 4′-methylbiphenylyl Group, 4 "-t-butyl-p-terphenyl-4-yl group, 2-fluorenyl group, 9,9-dimethyl-2-fluorenyl group, 3-fluoranthenyl group and the like.

  Preferably a phenyl group, 1-naphthyl group, 2-naphthyl group, 9-phenanthryl group, 1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group, 2-biphenylyl group, 3-biphenylyl group, 4-biphenylyl group, o-tolyl group, m-tolyl group, p-tolyl group, pt-butylphenyl group, 2-fluorenyl group, 9,9- A dimethyl-2-fluorenyl group, a 3-fluoranthenyl group, etc. are mentioned.

  Examples of the substituted or unsubstituted styryl group include 2-phenyl-1-vinyl group, 2,2-diphenyl-1-vinyl group, 1,2,2-triphenyl-1-vinyl group, and the like.

p is an integer of 1 to 4.
When p ≧ 2, p Ar ³ and Ar ⁴ may be the same or different.

Specific examples of the compound represented by the formula (2) are shown below.

(4) Hole transport layer In this invention, a hole transport layer can be provided between a light emitting layer and a hole injection layer.
The hole transport layer is preferably a material that transports holes to the light emitting layer with lower electric field strength. That is, the mobility of holes is preferably 10 ⁻⁴ cm ² / V · sec or more when an electric field of 10 ⁴ to 10 ⁶ V / cm is applied.

  The material for forming the hole transport layer is selected from materials commonly used as charge transport materials for holes in photoconductive materials and known materials used for hole transport layers in EL devices. Can be used.

  Specific examples include triazole derivatives (see US Pat. No. 3,112,197), oxadiazole derivatives (see US Pat. No. 3,189,447, etc.), imidazole derivatives (Japanese Patent Publication No. 37-16096). Polyarylalkane derivatives (US Pat. Nos. 3,615,402, 3,820,989, 3,542,544, JP-B-45-555). 51-10983, JP-A-51-93224, 55-17105, 56-4148, 55-108667, 55-156953, 56-36656 Patent Publication etc.), pyrazoline derivatives and pyrazolone derivatives (US Pat. Nos. 3,180,729, 4,278,746, Sho 55-88064, 55-88065, 49-105537, 55-51086, 56-80051, 56-88141, 57-45545, 54-112737, 55-74546, etc.), phenylenediamine derivatives (US Pat. No. 3,615,404, JP-B 51-10105, 46-3712, 47- No. 25336, Japanese Patent Laid-Open Nos. 54-53435, 54-110536, 54-1119925, etc.), arylamine derivatives (US Pat. No. 3,567,450, No. 3, 180,703 specification, 3,240,597 specification, 3,658,520 specification, 4,232,103 specification No. 4,175,961, No. 4,012,376, JP-B-49-35702, JP-A-39-27577, JP-A-55-144250, JP-A-56. 119132, 56-22437, West German Patent 1,110,518, etc.), amino-substituted chalcone derivatives (see US Pat. No. 3,526,501, etc.), oxazole derivatives (see U.S. Pat. No. 3,257,203), styryl anthracene derivatives (see JP-A-56-46234, etc.), fluorenone derivatives (see JP-A-54-110837, etc.), hydrazone Derivatives (US Pat. No. 3,717,462, JP-A-54-59143, 55-52063, 55-52064) 55-46760, 55-85495, 57-11350, 57-148799, JP-A-2-311591, etc.), stilbene derivatives (JP-A-61-210363) Gazette, 61-228451, 61-14642, 61-72255, 62-47646, 62-36684, 62-10652, 62-30255 No. 60-93455, No. 60-94462, No. 60-174749, No. 60-175052, etc.), silazane derivatives (US Pat. No. 4,950,950), polysilane System (JP-A-2-204996), aniline copolymer (JP-A-2-282263), JP-A-1-21 Conductive polymer oligomers disclosed in 399 JP can (particularly thiophene oligomer).

  The hole transport layer can be formed from the above-described compound by a known method such as a vacuum deposition method, a spin coating method, a casting method, or an LB method. The film thickness of the hole transport layer is not particularly limited, but is preferably 5 nm to 1 μm. The hole transport layer may be composed of one or more of the above materials. Also, a hole transport layer made of another kind of compound may be laminated.

(5) Hole Injecting Layer The same material as the hole transporting layer can be used as the material for the hole injecting layer, but a porphyrin compound (disclosed in Japanese Patent Laid-Open No. 63-295965), aromatic Group tertiary amine compounds and styrylamine compounds (US Pat. No. 4,127,412, JP-A-53-27033, 54-58445, 54-149634, 54-64299) No. 55-79450, No. 55-144250, No. 56-119132, No. 61-295558, No. 61-98353, No. 63-295695, etc.), especially fragrance It is preferable to use a group III tertiary amine compound.

  Further, for example, 4,4′-bis (N- (1-naphthyl) -N-phenylamino) biphenyl having two condensed aromatic rings described in US Pat. No. 5,061,569 in the molecule. (Hereinafter abbreviated as NPD), and 4,4 ′, 4 ″ -tris (N- (3−3) in which three triphenylamine units described in JP-A-4-308688 are linked in a starburst type. And methylphenyl) -N-phenylamino) triphenylamine (hereinafter abbreviated as MTDATA).

In addition to aromatic dimethylidin compounds, inorganic compounds such as p-type Si and p-type SiC can also be used as the material for the hole injection layer. The organic semiconductor layer is also a part of the hole injection layer, which is a layer that assists hole injection or electron injection into the light emitting layer, and preferably has a conductivity of 10 ⁻¹⁰ S / cm or more. It is. As a material for such an organic semiconductor layer, a conductive oligomer such as a thiophene-containing oligomer, an arylamine oligomer disclosed in JP-A-8-193191, a conductive dendrimer such as an arylamine dendrimer, or the like is used. Can do.

The hole injection layer can be formed of the above-described compound by a known method such as a vacuum deposition method, a spin coating method, a casting method, or an LB method.
The film thickness as the hole injection layer is preferably 40 nm to 1000 nm in order to avoid damage during film formation of the anode. More preferably, it is 60-300 nm, More preferably, it is 100-200 nm.

  The hole injection layer may be composed of one or more layers made of the above materials. Alternatively, a hole injection layer made of a compound different from the hole injection layer may be laminated.

(6) Electron transport layer In this invention, an electron transport layer can be provided between a cathode and a light emitting layer.
The electron transport layer is appropriately selected with a film thickness of several nm to several μm, but preferably has an electron mobility of 10 ⁻⁵ cm ² / Vs or more when an electric field of 10 ⁴ to 10 ⁶ V / cm is applied.

As a material used for the electron transport layer, a metal complex of 8-hydroxyquinoline or a derivative thereof is preferable.
Specific examples of the metal complex of 8-hydroxyquinoline or a derivative thereof include metal chelate oxinoid compounds containing a chelate of oxine (generally 8-quinolinol or 8-hydroxyquinoline).

  For example, Alq described in the section of the light emitting material can be used as the electron injection layer.

（式中、Ａｒ^５，Ａｒ^６，Ａｒ^７，Ａｒ^９，Ａｒ^１０，Ａｒ^１３はそれぞれ置換又は無置換のアリール基を示し、それぞれ互いに同一であっても異なっていてもよい。またＡｒ^８，Ａｒ^１１，Ａｒ^１２は置換又は無置換のアリーレン基を示し、それぞれ同一であっても異なっていてもよい） On the other hand, examples of the oxadiazole derivative include an electron transfer compound represented by the following formula.

(In the formula, Ar ⁵ , Ar ⁶ , Ar ⁷ , Ar ⁹ , Ar ¹⁰ , Ar ¹³ each represents a substituted or unsubstituted aryl group, and may be the same or different from each other. Ar ⁸ , Ar ¹¹ and Ar ¹² represent a substituted or unsubstituted arylene group, which may be the same or different.

  Here, examples of the aryl group include a phenyl group, a biphenyl group, an anthranyl group, a perylenyl group, and a pyrenyl group. Examples of the arylene group include a phenylene group, a naphthylene group, a biphenylene group, an anthranylene group, a peryleneylene group, and a pyrenylene group. Examples of the substituent include an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and a cyano group. This electron transfer compound is preferably a thin film-forming compound.

Specific examples of the electron transfer compound include the following.

（式中、Ａ^１〜Ａ^３は、窒素原子又は炭素原子である。
Ｒは、置換基を有していてもよい炭素数６〜６０のアリール基、置換基を有していてもよい炭素数３〜６０のヘテロアリール基、炭素数１〜２０のアルキル基、炭素数１〜２０のハロアルキル基、炭素数１〜２０のアルコキシ基であり、ｎは０から５の整数であり、ｎが２以上の整数であるとき、複数のＲは互いに同一又は異なっていてもよい。
また、隣接する複数のＲ基同士で互いに結合して、置換又は未置換の炭素環式脂肪族環、あるいは、置換又は未置換の炭素環式芳香族環を形成していてもよい。
Ａｒ^１４は、置換基を有していてもよい炭素数６〜６０のアリール基、置換基を有していてもよい炭素数３〜６０のヘテロアリール基である。
Ａｒ^１５は、水素原子、炭素数１〜２０のアルキル基、炭素数１〜２０のハロアルキル基、炭素数１〜２０のアルコキシ基、置換基を有していてもよい炭素数６〜６０のアリール基、置換基を有していてもよい炭素数３〜６０のヘテロアリール基である。
ただし、Ａｒ^１４、Ａｒ^１５のいずれか一方は置換基を有していてもよい炭素数１０〜６０の縮合環基、置換基を有していてもよい炭素数３〜６０のヘテロ縮合環基である。
Ｌ^１、Ｌ^２は、それぞれ単結合、置換基を有していてもよい炭素数６〜６０の縮合環、置換基を有していてもよい炭素数３〜６０のヘテロ縮合環又は置換基を有していてもよいフルオレニレン基である。） Nitrogen-containing heterocyclic derivative represented by the following formula

^(Wherein, A 1 to A ³ is a nitrogen atom or a carbon atom.
R is an aryl group having 6 to 60 carbon atoms which may have a substituent, a heteroaryl group having 3 to 60 carbon atoms which may have a substituent, an alkyl group having 1 to 20 carbon atoms, carbon A haloalkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, n is an integer of 0 to 5, and when n is an integer of 2 or more, a plurality of Rs may be the same or different from each other Good.
Further, a plurality of adjacent R groups may be bonded to each other to form a substituted or unsubstituted carbocyclic aliphatic ring or a substituted or unsubstituted carbocyclic aromatic ring.
Ar ¹⁴ is an aryl group having 6 to 60 carbon atoms which may have a substituent and a heteroaryl group having 3 to 60 carbon atoms which may have a substituent.
Ar ¹⁵ is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a haloalkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an aryl having 6 to 60 carbon atoms which may have a substituent. A heteroaryl group having 3 to 60 carbon atoms which may have a group or a substituent.
However, any one of Ar ¹⁴ and Ar ¹⁵ may have a substituent, a C10-60 condensed ring group, and a C3-60 heterocondensed ring group, which may have a substituent. It is.
L ¹ and L ² are each a single bond, a condensed ring having 6 to 60 carbon atoms which may have a substituent, a hetero condensed ring having 3 to 60 carbon atoms which may have a substituent, or a substituent. It is a fluorenylene group which may have )

Nitrogen-containing heterocyclic derivative represented by the following formula ^{HAr-L 3 -Ar} 16 -Ar ¹⁷
(Wherein HAr is a nitrogen-containing heterocycle having 3 to 40 carbon atoms which may have a substituent,
L ³ has a single bond, an arylene group having 6 to 60 carbon atoms which may have a substituent, a heteroarylene group having 3 to 60 carbon atoms which may have a substituent, or a substituent. A fluorenylene group that may be
Ar ¹⁶ is a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent,
Ar ¹⁷ is an aryl group having 6 to 60 carbon atoms which may have a substituent, or
It is a C3-C60 heteroaryl group which may have a substituent. )

（式中、Ｑ^１及びＱ^２は、それぞれ独立に炭素数１から６までの飽和若しくは不飽和の炭化水素基、アルコキシ基、アルケニルオキシ基、アルキニルオキシ基、ヒドロキシ基、置換若しくは無置換のアリール基、置換若しくは無置換のヘテロ環又はＱ^１とＱ^２が結合して飽和又は不飽和の環を形成した構造であり、Ｒ^１〜Ｒ^４は、それぞれ独立に水素、ハロゲン、置換もしくは無置換の炭素数１から６までのアルキル基、アルコキシ基、アリールオキシ基、パーフルオロアルキル基、パーフルオロアルコキシ基、アミノ基、アルキルカルボニル基、アリールカルボニル基、アルコキシカルボニル基、アリールオキシカルボニル基、アゾ基、アルキルカルボニルオキシ基、アリールカルボニルオキシ基、アルコキシカルボニルオキシ基、アリールオキシカルボニルオキシ基、スルフィニル基、スルフォニル基、スルファニル基、シリル基、カルバモイル基、アリール基、ヘテロ環基、アルケニル基、アルキニル基、ニトロ基、ホルミル基、ニトロソ基、ホルミルオキシ基、イソシアノ基、シアネート基、イソシアネート基、チオシアネート基、イソチオシアネート基もしくはシアノ基又は隣接した場合には置換若しくは無置換の環が縮合した構造である。） An electroluminescent device using a silacyclopentadiene derivative represented by the following formula, as disclosed in JP-A-09-087616

(Wherein Q ¹ and Q ² are each independently a saturated or unsaturated hydrocarbon group having 1 to 6 carbon atoms, alkoxy group, alkenyloxy group, alkynyloxy group, hydroxy group, substituted or unsubstituted aryl group) A group, a substituted or unsubstituted heterocycle, or a structure in which Q ¹ and Q ² are combined to form a saturated or unsaturated ring, and R ^{1 to} R ⁴ are each independently hydrogen, halogen, substituted or unsubstituted Alkyl group having 1 to 6 carbon atoms, alkoxy group, aryloxy group, perfluoroalkyl group, perfluoroalkoxy group, amino group, alkylcarbonyl group, arylcarbonyl group, alkoxycarbonyl group, aryloxycarbonyl group, azo group Alkylcarbonyloxy group, arylcarbonyloxy group, alkoxycarbonyloxy group, Reeloxycarbonyloxy group, sulfinyl group, sulfonyl group, sulfanyl group, silyl group, carbamoyl group, aryl group, heterocyclic group, alkenyl group, alkynyl group, nitro group, formyl group, nitroso group, formyloxy group, isocyano group, (Cyanate group, isocyanate group, thiocyanate group, isothiocyanate group or cyano group, or if adjacent, substituted or unsubstituted ring is condensed.)

（式中、Ｑ^３及びＱ^４は、それぞれ独立に炭素数１から６までの飽和もしくは不飽和の炭化水素基、アルコキシ基、アルケニルオキシ基、アルキニルオキシ基、置換もしくは無置換のアリール基、置換もしくは無置換のヘテロ環又はＱ^３とＱ^４が結合して飽和もしくは不飽和の環を形成した構造であり、Ｒ^５〜Ｒ^８は、それぞれ独立に水素、ハロゲン、置換もしくは無置換の炭素数１から６までのアルキル基、アルコキシ基、アリールオキシ基、パーフルオロアルキル基、パーフルオロアルコキシ基、アミノ基、アルキルカルボニル基、アリールカルボニル基、アルコキシカルボニル基、アリールオキシカルボニル基、アゾ基、アルキルカルボニルオキシ基、アリールカルボニルオキシ基、アルコキシカルボニルオキシ基、アリールオキシカルボニルオキシ基、スルフィニル基、スルフォニル基、スルファニル基、シリル基、カルバモイル基、アリール基、ヘテロ環基、アルケニル基、アルキニル基、ニトロ基、ホルミル基、ニトロソ基、ホルミルオキシ基、イソシアノ基、シアネート基、イソシアネート基、チオシアネート基、イソチオシアネート基、もしくはシアノ基又は隣接した場合には置換もしくは無置換の環が縮合した構造である（但し、Ｒ^５及びＲ^８がフェニル基の場合、Ｑ^３及びＱ^４は、アルキル基及びフェニル基ではなく、Ｒ^５及びＲ^８がチエニル基の場合、Ｑ^３及びＱ^４は、一価炭化水素基を、Ｒ^６及びＲ^７は、アルキル基、アリール基、アルケニル基又はＲ^６とＲ^７が結合して環を形成する脂肪族基を同時に満たさない構造であり、Ｒ^５及びＲ^８がシリル基の場合、Ｒ^６、Ｒ^７、Ｑ^３及びＱ^４は、それぞれ独立に、炭素数１から６の一価炭化水素基又は水素原子でなく、Ｒ^５及びＲ^６でベンゼン環が縮合した構造の場合、Ｑ^３及びＱ^４は、アルキル基及びフェニル基ではない。）） A silacyclopentadiene derivative represented by the following formula disclosed in JP-A No. 09-194487

Wherein Q ³ and Q ⁴ are each independently a saturated or unsaturated hydrocarbon group having 1 to 6 carbon atoms, an alkoxy group, an alkenyloxy group, an alkynyloxy group, a substituted or unsubstituted aryl group, a substituted group Or an unsubstituted heterocyclic ring or a structure in which Q ³ and Q ⁴ are combined to form a saturated or unsaturated ring, and R ^{5 to} R ⁸ are independently hydrogen, halogen, substituted or unsubstituted carbon number. 1 to 6 alkyl groups, alkoxy groups, aryloxy groups, perfluoroalkyl groups, perfluoroalkoxy groups, amino groups, alkylcarbonyl groups, arylcarbonyl groups, alkoxycarbonyl groups, aryloxycarbonyl groups, azo groups, alkylcarbonyls Oxy group, arylcarbonyloxy group, alkoxycarbonyloxy group, aryloxy Sicarbonyloxy group, sulfinyl group, sulfonyl group, sulfanyl group, silyl group, carbamoyl group, aryl group, heterocyclic group, alkenyl group, alkynyl group, nitro group, formyl group, nitroso group, formyloxy group, isocyano group, cyanate A group, an isocyanate group, a thiocyanate group, an isothiocyanate group, or a cyano group or, when adjacent, a substituted or unsubstituted ring is condensed (provided that when R ⁵ and R ⁸ are phenyl groups, Q ³ and Q ⁴ is not an alkyl group or a phenyl group, and when R ⁵ and R ⁸ are thienyl groups, Q ³ and Q ⁴ are monovalent hydrocarbon groups, R ⁶ and R ⁷ are alkyl groups, aryl groups, alkenyl group, or R ⁶ and R ⁷ are bonded to a structure that does not satisfy the aliphatic group simultaneously forming a ring, R ⁵ and R If is a silyl ^group, R ^6, R 7, ^{Q 3} and ^{Q 4} are each independently, not a monovalent hydrocarbon group or a hydrogen atom from 1 to 6 carbon atoms, a benzene ring is fused with ^{R 5} and ^{R 6} In the structure, Q ³ and Q ⁴ are not an alkyl group or a phenyl group.))

（式中、Ｒ^９〜Ｒ^１６及びＱ^８は、それぞれ独立に、水素原子、飽和もしくは不飽和の炭化水素基、芳香族基、ヘテロ環基、置換アミノ基、置換ボリル基、アルコキシ基又はアリールオキシ基を示し、Ｑ^５、Ｑ^６及びＱ^７は、それぞれ独立に、飽和もしくは不飽和の炭化水素基、芳香族基、ヘテロ環基、置換アミノ基、アルコキシ基又はアリールオキシ基を示し、Ｑ^７とＱ^８の置換基は相互に結合して縮合環を形成してもよく、ｒは１〜３の整数を示し、ｒが２以上の場合、Ｑ^７は異なってもよい。但し、ｒが１、Ｑ^５、Ｑ^６及びＲ^１０がメチル基であって、Ｒ^１６が水素原子又は置換ボリル基の場合、及びｒが３でＱ^７がメチル基の場合を含まない。） A borane derivative represented by the following formula disclosed in Japanese Patent Publication No. 2000-040586

(In the formula, R ^{9 to} R ¹⁶ and Q ⁸ are each independently a hydrogen atom, a saturated or unsaturated hydrocarbon group, an aromatic group, a heterocyclic group, a substituted amino group, a substituted boryl group, an alkoxy group, or aryl. Q ⁵ , Q ⁶ and Q ⁷ each independently represents a saturated or unsaturated hydrocarbon group, aromatic group, heterocyclic group, substituted amino group, alkoxy group or aryloxy group; The substituents of ⁷ and Q ⁸ may be bonded to each other to form a condensed ring, and r represents an integer of 1 to 3, and when r is 2 or more, Q ⁷ may be different, provided that r 1, Q ⁵ , Q ⁶ and R ¹⁰ are methyl groups, R ¹⁶ is a hydrogen atom or a substituted boryl group, and r is 3 and Q ⁷ is a methyl group.

（式中、Ｑ^９，Ｑ^１０は、それぞれ独立に、下記式（３）で示される配位子を表し、Ｌ^４は、ハロゲン原子、置換もしくは未置換のアルキル基、置換もしくは未置換のシクロアルキル基、置換もしくは未置換のアリール基、置換もしくは未置換の複素環基、−ＯＲ^1７（Ｒ^1７は水素原子、置換もしくは未置換のアルキル基、置換もしくは未置換のシクロアルキル基、置換もしくは未置換のアリール基、置換もしくは未置換の複素環基である。）又は−Ｏ−Ｇａ−Ｑ^１１（Ｑ^１２）（Ｑ^１１及びＱ^１２は、Ｑ^９及びＱ^１０と同じ意味を表す。）で示される配位子を表す。） A compound represented by the following formula shown in JP-A-10-088121

(In the formula, Q ⁹ and Q ¹⁰ each independently represent a ligand represented by the following formula (3), and L ⁴ represents a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cyclohexane. An alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, —OR ¹⁷ (R ¹⁷ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted group; A substituted aryl group, a substituted or unsubstituted heterocyclic group) or —O—Ga—Q ¹¹ (Q ¹² ) (Q ¹¹ and Q ¹² represent the same meaning as Q ⁹ and Q ¹⁰ ). Represents the ligand shown.)

（式中、環Ａ^４及びＡ^５は、置換基を有してよい互いに縮合した６員アリール環構造である。）
この金属錯体はｎ型半導体としての性質が強く、電子注入能力が大きい。さらには、錯体形成時の生成エネルギーも低いために、形成した金属錯体の金属と配位子との結合性も強固になり、発光材料としての蛍光量子効率も大きくなっている。

(Wherein rings A ⁴ and A ⁵ are 6-membered aryl ring structures condensed with each other which may have a substituent)
This metal complex has strong properties as an n-type semiconductor and has a large electron injection capability. Furthermore, since the generation energy at the time of complex formation is also low, the bond between the metal of the formed metal complex and the ligand is strengthened, and the fluorescence quantum efficiency as a light emitting material is also increased.

Specific examples of the substituents of the rings A ⁴ and A ⁵ that form the ligand of the above formula include chlorine, bromine, iodine, halogen atoms of fluorine, methyl group, ethyl group, propyl group, butyl group, substituted or unsubstituted alkyl groups such as sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, stearyl group, trichloromethyl group, phenyl group, naphthyl group, 3-methylphenyl group, 3-methoxyphenyl group, 3-fluorophenyl group, 3-trichloromethylphenyl group, 3-trifluoromethylphenyl group, substituted or unsubstituted aryl group such as 3-nitrophenyl group, methoxy group, n-butoxy group, tert-butoxy group, trichloromethoxy group, trifluoroethoxy group, pentafluoropropoxy group, 2,2,3,3- Substituted or unsubstituted alkoxy groups such as trifluoropropoxy group, 1,1,1,3,3,3-hexafluoro-2-propoxy group, 6- (perfluoroethyl) hexyloxy group, phenoxy group, p- Nitrophenoxy group, p-tert-butylphenoxy group, 3-fluorophenoxy group, pentafluorophenyl group, substituted or unsubstituted aryloxy group such as 3-trifluoromethylphenoxy group, methylthio group, ethylthio group, tert-butylthio Group, hexylthio group, octylthio group, trifluoromethylthio group and other substituted or unsubstituted alkylthio groups, phenylthio group, p-nitrophenylthio group, tert-butylphenylthio group, 3-fluorophenylthio group, pentafluorophenylthio group Group, 3-trifluoromethyl Monophenyls such as substituted or unsubstituted arylthio groups such as ruphenylthio groups, cyano groups, nitro groups, amino groups, methylamino groups, diethylamino groups, ethylamino groups, diethylamino groups, dipropylamino groups, dibutylamino groups, diphenylamino groups, etc. Or an acylamino group such as a di-substituted amino group, bis (acetoxymethyl) amino group, bis (acetoxyethyl) amino group, bisacetoxypropyl) amino group, bis (acetoxybutyl) amino group, hydroxyl group, siloxy group, acyl group, methyl Carbamoyl group, dimethylcarbamoyl group, ethylcarbamoyl group, diethylcarbamoyl group, propylcarbamoyl group, butylcarbamoyl group, phenylcarbamoyl group, etc.carbamoyl group, carboxylic acid group, sulfonic acid group, imide group, cyclopentane group, Cycloalkyl group such as hexyl group, phenyl group, naphthyl group, biphenyl group, anthranyl group, aryl group such as phenanthryl group, fluorenyl group, pyrenyl group, pyridinyl group, pyrazinyl group, pyrimidinyl group, pyridazinyl group, triazinyl group, indolinyl group , Quinolinyl group, acridinyl group, pyrrolidinyl group, dioxanyl group, piperidinyl group, morpholidinyl group, piperazinyl group, triatinyl group, carbazolyl group, furanyl group, thiophenyl group, oxazolyl group, oxadiazolyl group, benzooxazolyl group, thiazolyl group And heterocyclic groups such as thiadiazolyl group, benzothiazolyl group, triazolyl group, imidazolyl group, benzoimidazolyl group, and pranyl group. Moreover, the above substituents may combine to form a further 6-membered aryl ring or heterocyclic ring.

(7) Electron Injection Layer In the present invention, an electron injection layer made of an insulator or a semiconductor can be provided between the cathode and the electron injection layer or between the cathode and the light emitting layer. By providing such an electron injection layer, current leakage is effectively prevented, and the electron injection property is improved.
As the insulator, alkali metal chalcogenide, alkaline earth metal chalcogenide, alkali metal halide and alkaline earth metal halide, aluminum oxide, aluminum nitride, titanium oxide, silicon oxide, germanium oxide, silicon nitride, boron nitride, It is preferable to use metal compounds such as molybdenum oxide, ruthenium oxide and vanadium oxide alone or in combination. Among these metal compounds, alkali metal chalcogenides and alkaline earth metal chalcogenides are preferable from the viewpoint of electron injection. Preferred alkali metal chalcogenides include Li ₂ O, LiO, Na ₂ S, Na ₂ Se, and NaO. Preferred alkaline earth metal chalcogenides include CaO, BaO, SrO, BeO, BaS, and CaSe. Examples of the alkali metal halide include LiF, NaF, KF, LiCl, KCl, and NaCl. Examples of the alkaline earth metal halide include fluorides such as CaF ₂ , BaF ₂ , SrF ₂ , MgF ₂ and BeF ₂ , and halides other than fluorides.

  As a semiconductor constituting the electron transport layer, at least one element selected from the group consisting of Ba, Ca, Sr, Yb, Al, Ga, In, Li, Na, Cd, Mg, Si, Ta, Sb, and Zn is used. One kind or a combination of two or more kinds of oxides, nitrides, oxynitrides and the like are included.

The electron injection layer is preferably microcrystalline or amorphous. This is because a uniform thin film is formed, so that pixel defects such as dark spots can be reduced.
Two or more kinds of electron injection layers may be laminated and used.

(8) Reducing dopant In this invention, a reducing dopant can be contained in the area | region which conveys an electron, or the interface area | region of a cathode and an organic layer. A reducing dopant refers to a substance that can reduce an electron transporting compound. Accordingly, various materials can be used as long as they have reducibility. For example, alkali metal, alkaline earth metal, rare earth metal, alkali metal oxide, alkali metal halide, alkaline earth metal oxide, alkaline earth metal halide, rare earth metal oxide or rare earth metal A halide, an alkali metal organic complex, an alkaline earth metal organic complex, a rare earth metal organic complex, or the like can be preferably used.
Preferred reducing dopants include alkali metals such as Na (work function: 2.36 eV), K (work function: 2.28 eV), Rb (work function: 2.16 eV) and Cs (work function: 1.95 eV). And Lucari earth metals such as Ca (work function: 2.9 eV), Sr (work function: 2.0 to 2.5 eV), and Ba (work function: 2.52 eV). Among these, K, Rb, and Cs are preferable, Rb or Cs is more preferable, and Cs is more preferable. A combination of two or more alkali metals is also preferable, and a combination including Cs, for example, a combination of Cs and Na, Cs and K, Cs and Rb, or Cs, Na, and K is particularly preferable.

(9) Cathode The cathode preferably uses a metal, an alloy, an electrically conductive compound and a mixture thereof having a low work function (4 eV or less) as an electrode material. Specific examples include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / silver alloy, aluminum / aluminum oxide, aluminum / lithium alloy, indium, rare earth metal, and the like.

The cathode preferably includes a metal oxide.
As metal oxides, Li _x Ti ₂ O ₄ , Li _x V ₂ O ₄ , Er _x NbO ₃ , La _x TiO ₃ , Sr _x VO ₃ , Ca _x CrO ₃ and Sr _x CrO ₃ (x = 0.2 to And at least one metal oxide selected from the group consisting of 5). Further, as the metal _{oxide, A x MoO 3 (A =} K, Cs, Rb, Sr, Na, Li, Ca) (x = 0.2~5), and _{A x V 2 O 5 (A} = K, Examples thereof include at least one metal oxide selected from Cs, Rb, Sr, Na, Li, Ca) (x = 0.2 to 5).

  The cathode further preferably contains at least one metal selected from alkali metals and alkaline earth metals in order to improve the electric injection property. Suitable metals include Na, K, Cs, and Mg.

The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering.
In the case where light emitted from the light emitting layer is taken out from the cathode side, it is preferable that the transmittance of the cathode for light emission is greater than 10%. More preferably, it is 30% or more, and further preferably 50% or more.

The cathode sheet resistance is preferably 1000Ω / □ or less. More preferably. 800Ω / □, more preferably 600Ω / □ The film thickness is not particularly limited, but is preferably 10 nm to 1 μm, more preferably 50 to 200 nm.
In addition, when taking out light emission from the anode side, it is preferable to make a cathode into a reflective electrode.

(10) Metal oxide layer The metal oxide contained in the metal oxide layer is preferably an oxide of a metal element belonging to Groups 3 to 13 of the long-term periodic table. Among these, a metal oxide composed of at least one selected from the group consisting of molybdenum oxide, vanadium oxide, rhenium oxide, ruthenium oxide, tungsten oxide, zinc oxide, titanium oxide and copper oxide is preferable.

As a method for forming the metal oxide layer, it is preferable to use a method that does not damage the light-emitting layer by a known method such as that used for manufacturing an organic EL element. For example, vapor deposition, spin coating, ink jet, and the like.
In the case of forming by vapor deposition, molybdenum trioxide or the like is preferably used.
Although there is no restriction | limiting in particular in a film thickness, 0.1 nm-10 micrometers are preferable, More preferably, they are 1 nm-1000 nm.

(11) Metal layer A metal layer can be provided between the metal oxide layer and the anode.
The metal layer is formed from, for example, an alloy containing at least one selected from Mg, Ag, and Zr.
Although there is no restriction | limiting in particular in a film thickness, 0.1 nm-10 micrometers are preferable, More preferably, they are 1 nm-15 nm.

(12) Preparation Example of Organic EL Element A preparation example of an organic EL element having a structure in which a cathode / electron transport layer / light emitting layer / hole injection layer / metal oxide layer / anode are sequentially provided on a substrate will be given.
A thin film made of a cathode material is formed on a substrate by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably in the range of 10 to 200 nm, to produce a cathode. Next, an electron transport layer is provided on the cathode. The electron transport layer can be formed by methods such as vacuum deposition, spin coating, casting, and LB, but it is easy to obtain a uniform film and pinholes are not easily generated. It is preferable to form by vacuum evaporation. When an electron transport layer is formed by a vacuum deposition method, the deposition conditions vary depending on the compound used (material of the electron transport layer), the crystal structure and recombination structure of the target electron transport layer, etc., but generally the deposition source temperature is 50. It is preferable to select as appropriate in a range of ˜450 ° C., a degree of vacuum of 10 ⁻⁷ to 10 ⁻³ torr, a deposition rate of 0.01 to 50 nm / second, a substrate temperature of −50 to 300 ° C., and a film thickness of 5 nm to 5 μm.

  Next, the light-emitting layer is formed on the electron transport layer by forming the organic light-emitting material into a thin film by a method such as vacuum deposition, sputtering, spin coating, or casting using a desired organic light-emitting material. Although it can be formed, it is preferably formed by a vacuum deposition method from the viewpoint that a homogeneous film is easily obtained and pinholes are hardly generated. When the light emitting layer is formed by the vacuum vapor deposition method, the vapor deposition condition varies depending on the compound used, but can be generally selected from the same condition range as that of the electron transport layer.

  Next, a hole injection layer is provided on the light emitting layer. As with the electron transport layer and the light emitting layer, it is preferable to form by a vacuum evaporation method because it is necessary to obtain a homogeneous film. The vapor deposition conditions can be selected from the same condition ranges as those for the electron transport layer and the light emitting layer.

A metal oxide layer is formed from several nm to several hundred nm on the hole injection material. The metal oxide layer can be formed by various methods, and specifically, vacuum deposition, sputtering, electron beam deposition, and the like. Vacuum deposition is preferred because of less damage to the hole injection layer. When a metal oxide layer is formed by a vacuum deposition method, the deposition conditions vary depending on the compound used, the crystal structure and recombination structure of the target metal oxide layer, etc., but generally the deposition source temperature is 50 to 500 ° C., vacuum It is preferable to select appropriately within a range of 10 ⁻⁷ to 10 ⁻³ torr, a deposition rate of 0.01 to 50 nm / second, a substrate temperature of −50 to 300 ° C., and a film thickness of 1 nm to 20 nm.
Finally, an anode can be laminated to obtain an organic EL element.

  For the anode, vapor deposition or sputtering can be used. However, vacuum deposition is preferred to protect the underlying organic layer from damage during film formation. The film thickness is usually 10 nm to 10 μm, preferably 10 nm to 1 μm.

  The organic EL elements described so far are preferably produced from the cathode to the anode consistently by a single evacuation.

  In addition, the formation method of each layer of the organic EL element of this invention is not specifically limited. Conventionally known methods such as vacuum deposition and spin coating can be used. The organic thin film layer used in the organic EL device of the present invention can be formed by vacuum deposition, molecular beam deposition (MBE) or solvent dipping method, spin coating method, casting method, bar coating method, roll coating method. It can be formed by a known method such as a coating method.

  The film thickness of each organic layer of the organic EL device of the present invention is not particularly limited. Generally, if the film thickness is too thin, defects such as pinholes are likely to occur. Conversely, if it is too thick, a high applied voltage is required and the efficiency is deteriorated. Therefore, the range of several nm to 1 μm is usually preferable.

Example 1
25 mm × 75 mm × 1.1 mm thick Ag (film thickness 20 nm) and ITO (film thickness 130 nm) electrode-attached glass substrate (manufactured by Geomatic) is ultrasonically cleaned in isopropyl alcohol for 5 minutes, then electrical resistance After ultrasonic cleaning with 20 MΩm distilled water for 5 minutes and further ultrasonic cleaning in isopropyl alcohol for 5 minutes, the electrode-attached glass substrate was taken out and dried. Thereafter, UV ozone cleaning was immediately performed for 30 minutes using a UV ozone apparatus manufactured by Samco International Laboratory.

The glass substrate with the electrode after the cleaning was mounted on a substrate holder of a vacuum vapor deposition apparatus, and was evacuated to reach 1 × 10 ⁻⁵ Pa.

  First, on the surface on which the transparent electrode line is formed, the electrode is covered and Alq and Li are deposited as an electron injection layer at deposition rates of 0.1 nm / sec and 0.01 nm / sec, respectively. The film was formed to a thickness of 20 nm.

  On this film, a 40 nm-thick host (H1 shown below) was deposited at a deposition rate of 0.2 nm / sec. At this time, a dopant (D1 shown below) was vapor-deposited as a luminescent molecule at a vapor deposition rate of 0.01 nm / sec. This film functions as a light emitting layer.

  Further, an N, N, N ′, N′-tetra (4-biphenyl) -diaminobiphenylene (hereinafter referred to as TBDB) layer having a thickness of 20 nm was formed at a deposition rate of 0.1 nm / sec. This film functions as a hole transport layer.

  On this TBDP layer, N, N′-bis (N, N′-diphenyl-4-aminophenyl) -N, N-diphenyl-4,4′- with a deposition rate of 0.1 nm / sec and a film thickness of 60 nm is formed. A diamino-1,1′-biphenyl (hereinafter, TPD232) film was formed. This TPD232 film functions as a hole injection layer.

  Following the formation of the TPD232 film, MoO3 was deposited on the TPD232 film at a deposition rate of 0.02 nm / sec to form a 10 nm thick layer.

Next, ITO was deposited to a thickness of 100 nm by sputtering at a deposition rate of 0.4 nm / s.
Next, the initial performance was measured at a current density of 1 mA / cm ² with the light reflecting electrode side of the organic EL element as a cathode. As a result, the drive voltage was 4.5 V, 10 cd / A, CIEx, y = (0.16, 0.26).

For the leakage current, a voltage of 5 V was applied with a reverse bias, and the current value at that time was measured. The leakage current was 2 × 10 ⁻⁹ A / cm ² .
The lifetime measurement was performed at room temperature, and was evaluated by performing continuous energization according to the current value when the initial luminance was 3000 nit by constant current direct current drive. The half life is the elapsed time when the initial luminance is halved. The half life was 2000 hr.

Comparative Example 1
In Example 1, instead of MoO ₃ , an organic EL element was produced in the same manner except that Au was deposited at a deposition rate of 0.05 nm / sec at a film thickness of 5 nm.
The initial performance was a drive voltage of 7 V, 6.0 cd / A, CIEx, y = (0.16, 0.25). The leakage current was 1 × 10 ⁻⁶ A / cm ² . The half life was 1000 hr.

Example 2
In Example 1, after depositing MoO ₃ , Mg and Ag were co-deposited at a deposition rate of 1.5 nm / sec and 0.1 nm / sec at a film thickness of 1.5 nm and 0.1 nm, respectively. An EL element was produced.
The initial performance was a drive voltage of 5 V, 11 cd / A, CIEx, y = (0.15, 0.26). The leakage current was 5 × 10 ⁻⁹ A / cm ² . The half life was 2000 hr.

Example 3
In Example 1, a glass substrate was used instead of the electrode-attached glass substrate, and before depositing Alq and Li, metal Al was deposited at a deposition rate of 0.8 nm / sec to a film thickness of 100 nm, and Cs and Organic EL was conducted in the same manner except that MoO _x (x = 2 to 3) was co-evaporated at a deposition rate of 0.01 nm / sec and 0.1 nm / sec, respectively, to form a cathode by forming a film with a thickness of 1 nm. An element was produced.
The initial performance was a drive voltage of 4.5 V, 11 cd / A, CIEx, y = (0.16, 0.26). The leakage current was 3 × 10 ⁻⁹ A / cm ² . The half life was 2000 hr.

  The organic EL element and the organic EL display device of the present invention can be used for consumer and industrial displays, specifically, mobile phones, PDAs, car navigation systems, monitors, TVs and the like.

It is a figure which shows embodiment of the organic EL element of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Organic EL element 2 Board | substrate 3 Cathode 4 Light emitting layer 5 Metal oxide layer 6 Anode 6a Conductive film 6b Protective film 7 Metal layer

Claims (14)

  An organic electroluminescence device comprising a substrate and at least a cathode, a light emitting layer, a metal oxide layer and an anode laminated in this order.   2. The organic electro layer according to claim 1, wherein the metal oxide layer is made of at least one selected from the group consisting of molybdenum oxide, vanadium oxide, rhenium oxide, ruthenium oxide, tungsten oxide, zinc oxide, titanium oxide, and copper oxide. Luminescence element.   The organic electroluminescent element according to claim 1, wherein the anode is a transparent electrode and the cathode is a reflective electrode.   The organic electroluminescent element according to any one of claims 1 to 3, wherein the anode is formed by laminating a conductive film and a protective film in this order from the substrate side.   The protective film is made of an oxide, nitride or oxynitride of at least one element selected from the group consisting of Si, Ge, Mg, Ta, Ti, Zn, Sn, In, Pb and Bi. 5. The organic electroluminescence device according to 4.   The protective film is selected from the group consisting of Mo, V, Cr, W, Ni, Co, Mn, Ir, Pt, Pd, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, and Yb. The organic electroluminescence device according to claim 4, comprising an oxide, nitride, or oxynitride of at least one element.   The organic electroluminescent element according to claim 4, wherein the protective film is light transmissive.   The organic electroluminescent element according to claim 4, wherein a metal layer is provided between the conductive layer and the protective film.   The organic electroluminescence according to any one of claims 1 to 8, wherein a metal layer is provided between the metal oxide layer and the anode, or between the light emitting layer and the metal oxide layer. element.   The organic electroluminescence device according to claim 8 or 9, wherein the metal layer is made of an alloy containing at least one selected from Mg, Ag, and Zr.   The organic electroluminescent element according to any one of claims 1 to 10, wherein the cathode comprises at least one metal selected from alkali metals and alkaline earth metals and a metal oxide. The metal oxide contained in the cathode is Li _x Ti ₂ O ₄ , Li _x V ₂ O ₄ , Er _x NbO ₃ , La _x TiO ₃ , Sr _x VO ₃ , Ca _x CrO ₃ and Sr _x CrO ₃ (x The organic electroluminescence device according to claim 11, which is at least one metal oxide selected from the group consisting of = 0.2 to 5). The metal oxide contained in the cathode is A _x MoO ₃ (A = K, Cs, Rb, Sr, Na, Li, Ca) (x = 0.2 to 5), and A _x V ₂ O ₅ (A The organic electroluminescence device according to claim 11, which is at least one metal oxide selected from = K, Cs, Rb, Sr, Na, Li, Ca) (x = 0.2 to 5).   The display apparatus comprised including the organic electroluminescent element as described in any one of Claims 1-13.

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